This invention relates to filter assemblies and, in particular, to a new and improved filter assembly of the type which can be used for filtering hydraulic fluid used in powering hydraulic motors and the like.
A typical filter assembly includes a filter element mounted in a housing which provides support and mechanical protection for the filter element and also provides a flow path from the housing inlet, through the filter element to the housing outlet. When such a filter assembly is utilized in conjunction with a hydraulic motor which may be operated in the reverse direction, there will be a reverse flow of fluid from the filter assembly outlet to the inlet. It is undesirable to have this reverse fluid flow through the filter element itself since this would tend to flush filtered particles off the element back into the fluid stream.
Also, during operation there comes a time when the filter element becomes blocked or dirty and its filtering action is reduced or terminated. While the filter element is no longer functioning, it is still desirable to have the fluid flow path open until the filter element can be replaced, and also to provide an indication that the filter element is no longer functioning. This is sometimes referred to as a bypass operation, with the fluid flow from the filter assembly inlet to the outlet bypassing the filter element.
It is an object of the present invention to provide a new and improved filter assembly providing for the normal fluid flow path through the filter element, and also providing for bypass operation around a blocked filter element and providing for reverse flow through the filter assembly without going through the filter element. It is another object of the invention to provide such a filter assembly in which the inlet and outlet of the main housing can be reversed permitting installation of the filter assembly without regard to a required direction of flow. Other objects, advantages, features and results will more fully appear in the course of the following description.